'pulse-free' originates from the combination of 'pulse,' which comes from Latin 'pulsus,' meaning 'a beating,' and 'free,' from Old English 'frēo,' meaning 'not in bondage.'

'pulse' changed from the Latin word 'pulsus' and eventually became the modern English word 'pulse.' 'Free' evolved from Old English 'frēo' to its current form.

Initially, 'pulse' meant 'a beating or throbbing,' and 'free' meant 'not in bondage.' Together, 'pulse-free' evolved to mean 'lacking a detectable pulse.'